The present research starts out from the hypothesis derived from the previous work that conception of human nature may be another important contributing factors of educational practice besides conception of education. Taking conception of ability as the key conception of human nature, the present research was conducted under three purposes: (a) to understand teachers conception of ability in terms of malleability, (b) to explore the relationship between teachers’ beliefs in ability malleability and their attribution of students’ performance, as well as the relationship with (c) educational practice. 530 teachers from primary, junior high and high schools responded to the questioner consisted of measurement of ability conception and hypothesized stories. The results demonstrated that: (a) most teachers believe that ability is a malleable trait., (b) those believe in high malleability attribute students performance to effort, low malleability to ability, (c) those believe in high malleability believe in the effectiveness of education more than others, (d) those do not believe in malleability of ability incline to negative educational practice.  Finally, the suggestions to the teachers education based on the research results were discussed.